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MCP4728 #66

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merged 2 commits into from
May 21, 2024
Merged

MCP4728 #66

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a85b652
MCP4728 -> Add docstrings and type annotations
franz-sweepMe May 17, 2024
cf8f2ad
MCP4728 -> Handle colons in self.value
franz-sweepMe May 21, 2024
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124 changes: 84 additions & 40 deletions src/Switch-Arduino_MCP4728/main.py
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Original file line number Diff line number Diff line change
Expand Up @@ -25,28 +25,53 @@
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.

# SweepMe! driver
# *Module: Switch
# *Instrument: Arduino MCP4728

# SweepMe! device class
# Device: Arduino MCP4728

from __future__ import annotations

from pysweepme import EmptyDevice


class Device(EmptyDevice):
"""Base class to control MCP4728 boards through Arduino."""

description = """
<h3>Arduino MCP4728</h3>
<p>This driver allows to set output voltages at MCP 4728 boards with 12-bit resolution. It can control up to 8 boards, each with 4 pins.</p>
<p>
This driver allows to set output voltages at MCP 4728 boards with 12-bit resolution. It can control up to 8
boards, each with 4 pins.
</p>
<h4>Setup</h4>
<p>Load the Switch-Arduino_MCP.ino sketch onto your Arduino. Set <em>baudrate</em> to 115200 and <em>terminator</em> to "\n". Install the Adafruit_MCP4728 library on your Arduino.</p>
<p>
Load the Switch-Arduino_MCP.ino sketch onto your Arduino. Set <em>baudrate</em> to 115200 and
<em>terminator</em> to "\n". Install the Adafruit_MCP4728 library on your Arduino.
</p>
<h4>Parameters</h4>
<p>Set <em>Channel </em>to the pin number you want to set, or <em>all </em>to set all four channels. The voltage values must be passed as a colon-separated string: <em>1.0:2.5:0:4.2</em></p>
<p>The I&sup2;C address is set as integer 0-7, corresponding to the boards standard addresses 0x60-0x67 (HEX). You can check your devices' address by using an <a href="https://playground.arduino.cc/Main/I2cScanner/">I&sup2;C Scanner</a>.</p>
<p>The maximum voltage is defined by the Voltage reference, which can either be internal (2.048 V or 4.096 V by using 2x gain) or from an external source, e.g. the Arduino's 5 V or 3.3 V output. When using an external reference, the voltage must be given.</p>
<p>To use multiple MCPs, their I&sup2;C addresses need to be changed individually, as described <a href="https://github.com/jknipper/mcp4728_program_address">here</a>. Choose <em>Channel: all </em>and set a comma-separated list for <em>I2C Address: 0, 1, 2</em>.</p>
<p>
Set <em>Channel </em>to the pin number you want to set, or <em>all </em>to set all four channels. The
voltage values must be passed as a colon-separated string: <em>1.0:2.5:0:4.2</em>
</p>
<p>
The I&sup2;C address is set as integer 0-7, corresponding to the boards standard addresses 0x60-0x67 (HEX). You
can check your devices' address by using an
<a href="https://playground.arduino.cc/Main/I2cScanner/">I&sup2;C Scanner</a>.
</p>
<p>
The maximum voltage is defined by the Voltage reference, which can either be internal (2.048 V or 4.096 V by
using 2x gain) or from an external source, e.g. the Arduino's 5 V or 3.3 V output. When using an external
reference, the voltage must be given.
</p>
<p>
To use multiple MCPs, their I&sup2;C addresses need to be changed individually, as described
<a href="https://github.com/jknipper/mcp4728_program_address">here</a>. Choose <em>Channel: all </em>and
set a comma-separated list for <em>I2C Address: 0, 1, 2</em>.
</p>
"""

def __init__(self) -> None:
"""Initialize the Device Class."""
EmptyDevice.__init__(self)

self.shortname = "Arduino MCP4728"
Expand All @@ -60,6 +85,16 @@ def __init__(self) -> None:
"timeout": 5,
"baudrate": 115200,
}
self.port_str: str = ""
self.driver_name: str = ""
self.instance_key: str = ""

self.pin: int = 0
self.sweepmode: str = ""
self.reference_voltage: str = "Internal 4.096 V"
self.external_voltage: float = 5.0
self.value_list: list[float] = []
self.volt: float = 0

self.multi_pins = False
self.multi_mcp = False
Expand All @@ -71,7 +106,8 @@ def __init__(self) -> None:
"Output in %": "%",
}

def set_GUIparameter(self):
def set_GUIparameter(self) -> dict: # noqa: N802
"""Set standard GUI parameters for the SweepMe! software."""
return {
"Channel": ["0", "1", "2", "3", "all"],
"I2C Address": "0",
Expand All @@ -80,7 +116,8 @@ def set_GUIparameter(self):
"External voltage in V": 5.0,
}

def get_GUIparameter(self, parameter={}):
def get_GUIparameter(self, parameter: dict) -> None: # noqa: N802
"""Handle input from GUI."""
# Handle output pins
channel = parameter["Channel"]
if channel == "all":
Expand Down Expand Up @@ -116,18 +153,18 @@ def get_GUIparameter(self, parameter={}):
self.variables = []
self.units = []
for n in range(channel_num):
# If single channel, use the correct pin number
if channel_num == 1:
n = self.pin
self.variables.append(f"Channel{n}")
# If single channel, use the correct pin
pin = self.pin if channel_num == 1 else n
self.variables.append(f"Channel{pin}")
self.units.append(self.unit[self.sweepmode])

self.port_str = parameter["Port"]
self.driver_name = parameter["Device"]

""" here, semantic standard functions start that are called by SweepMe! during a measurement """

def connect(self):
def connect(self) -> None:
"""Initialize Arduino and register the device in the communication manager."""
# Set Name/Number of COM Port as key
self.instance_key = f"{self.driver_name}_{self.port_str}"

Expand All @@ -136,11 +173,13 @@ def connect(self):
self.port.read()
self.device_communication[self.instance_key] = "Connected"

def disconnect(self):
def disconnect(self) -> None:
"""Unregister the device from the communication manager."""
if self.instance_key in self.device_communication:
self.device_communication.pop(self.instance_key)

def configure(self):
def configure(self) -> None:
"""Configure the MCP4728 reference voltages."""
# Initialize single MCP4728 with given I2C address - multi MCPs are set in apply
if not self.multi_mcp:
self.set_address(self.addresses[0])
Expand All @@ -158,8 +197,8 @@ def configure(self):
self.set_vref(use_internal_vref=False)
self.max_voltage = self.external_voltage

def unconfigure(self):
# Set all outputs to 0
def unconfigure(self) -> None:
"""Set all outputs to 0 V after measurement finishes."""
if self.multi_pins:
for address in self.addresses:
self.set_address(address)
Expand All @@ -168,17 +207,20 @@ def unconfigure(self):
else:
self.set_voltage(self.pin, 0)

def apply(self):
def apply(self) -> None:
"""Set the voltages to the pins."""
if self.multi_pins:
# Receive values as list, split by ":" and convert to float
split_values = self.value.split(":")
self.value_list = list(map(float, split_values))
# Replace , with . to enable float conversion
dot_separated_values = self.value.replace(",", ".")
# Input values are separated by colons
sweep_values = dot_separated_values.split(":")
self.value_list = list(map(float, sweep_values))

# Adjust number of channels depending on number of boards and pins
number_of_channels = 4 * len(self.addresses) if self.multi_mcp else 4

if len(self.value_list) != number_of_channels:
msg = f"Incorrect number of voltages received. Expected {number_of_channels}, got {len(value_list)}"
msg = f"Incorrect number of voltages received. Expected {number_of_channels} got {len(self.value_list)}"
raise Exception(msg)

for n, value in enumerate(self.value_list):
Expand All @@ -188,7 +230,7 @@ def apply(self):
else:
volt_bit = self.voltage_to_12bit(value)

# Iterate through pin numbers (0-3) and initialize MCP for each pin=0
# Iterate through pins (0-3) and initialize MCP for each pin=0
pin = n % 4
if pin == 0:
mcp_num = int(n / 4)
Expand All @@ -211,24 +253,25 @@ def apply(self):

self.set_voltage(self.pin, volt_bit)

def call(self):
# Return values that are set to the pins
def call(self) -> list[float]:
"""Return the voltages set to the pins."""
return self.value_list if self.multi_pins else [self.volt]

""" here, convenience functions start """

def voltage_to_12bit(self, voltage, relative_voltage=False):
# Convert given voltage to integer between 0 and 4095 (max voltage)
def voltage_to_12bit(self, voltage: float, relative_voltage: bool = False) -> int:
"""Convert given voltage to integer between 0 and 4095 (max voltage)."""
voltage_bit = int(voltage / 100 * 4095) if relative_voltage else int(4095 / self.max_voltage * voltage)

if not 0 <= voltage_bit < 4096:
max_bit = 4095
if not 0 <= voltage_bit < max_bit:
msg = f"Voltage {voltage} out of bound. Either larger than max voltage or negative."
raise ValueError(msg)

return voltage_bit

def set_voltage(self, pin, bit_value):
# Send command to set voltage (in bit value) at given pin
def set_voltage(self, pin: int, bit_value: int) -> None:
"""Send command to set voltage (in bit) at given pin."""
command_string = f"CH{pin}={bit_value}"
self.port.write(command_string)

Expand All @@ -243,9 +286,10 @@ def set_voltage(self, pin, bit_value):
msg = f"Failed to set voltage of {bit_value} at pin {pin}. Arduino response: {ret}"
raise Exception(msg)

def set_address(self, address: int):
# Initialize MCP at Arduino to receive further commands
if not 0 <= address <= 7:
def set_address(self, address: int) -> None:
"""Initialize MCP at Arduino to receive further commands."""
max_address = 7
if not 0 <= address <= max_address:
msg = "I2C Address must be 0-7"
raise Exception(msg)

Expand All @@ -267,8 +311,8 @@ def set_address(self, address: int):
msg = f"Failed to set address to {address}. Arduino response: {ret}"
raise Exception(msg)

def set_vref(self, use_internal_vref=True):
# Set reference voltage as internal or external
def set_vref(self, use_internal_vref: bool = True) -> None:
"""Set reference voltage as internal or external."""
v_ref = "I" if use_internal_vref else "E"

command_string = f"VR={v_ref}"
Expand All @@ -280,8 +324,8 @@ def set_vref(self, use_internal_vref=True):
msg = f"Failed to set reference voltage (vref). Arduino response: {ret}"
raise Exception(msg)

def set_gain(self, gain):
# For internal reference voltage, choose 1x or 2x gain
def set_gain(self, gain: int) -> None:
"""For internal reference voltage, choose 1x or 2x gain."""
if gain not in [1, 2]:
msg = "gain can only be 1 or 2"
raise ValueError(msg)
Expand Down
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